Kai kurių polimerų laidumo tyrimas diferencinių voltamperinių charakteristikų metodu

• Main Author: Sadzevičius, Vilius
• Other Authors: Udris, Arvydas
• Format: Dissertation
• Language: Lithuanian
• Published: Lithuanian Academic Libraries Network (LABT) 2006
• Subjects: Physics; Voltamperinė; Polimerai; Conductivity; Polymer; Diferencinė; Laidumas; Nanofibers
• Online Access: http://vddb.library.lt/fedora/get/LT-eLABa-0001:E.02~2006~D_20060615_104319-43417/DS.005.0.01.ETD

Polymers, typically known, as plastics, long time were only insulators. In 1977 D.J. Heeger, A.G. Diarmid ir H. Shirakawa discovered a new type of this organic material – conductive polymers. Conductive polymers have a unique property of high electrical conductivity, where the electronic structure of polymer chains plays essential role. In this work we theoretically investigate conductive organic materials. Conductance of this materials is the result of charge carriers tunnelling. Tunnelling is a temperature-dependent process due to the interaction of electrons with phonons (phonon – kvaziparticle describing the periodical motion of cristal atoms). The basic quantum-mechanical theory what helps us to interpret the experimental results – phonon-assisted tunnelling theory. Experimental results were taken from other authors papers. In this theory is assumed that tunnelling rate depends on both – temperature and field. All the calculations were taken in Mathematica 5.0. Programs made in this algebrical system helped us to fit experimentical and theoretical data. It let us to describe tunnelling rate variating parameters. The main attention was taken to investigate how some of this parameters change tunnelling rate (W) and estimate parameters of polyacetylene and carbon nanotubes (CNT). This materials were taken because of it`s unique properties. Polyacetylene can become very good conductor by it`s doping. Carbon is one of the most abundant ellements in the Earth crust. It... [to full text]